Multiple companies construct mobile phone systems and provide various services. The state of wireless areas formed by both wireless base stations and terminal devices vary due to the time or locations. Consequently, the communication state in the wireless areas are improved by measuring the wireless quality in each of the wireless areas.
In general, a high-cost drive test is used for this measurement. In recent years, the Minimization of Drive Test (MDT) technology is used as a method of reducing the cost. The MDT technology measures the wireless quality in a wireless area by using a terminal device owned by a user in this area and automatically reports the measurement result to an operator. The pieces of quality information collected from terminal devices in this way are registered in databases in the companies that provide the mobile phone systems and are used to develop the quality.
Furthermore, there is a known technology, as a technology for changing the collecting period of the wireless quality, that changes a collecting period depending on the accuracy of location information on a terminal device that corrects the quality information. Furthermore, there is a known technology that changes a collecting period in accordance with the time intervals for which a terminal device collects information or in accordance with the state of a battery in the terminal device.
Patent Document 1: Japanese Laid-open Patent Publication No. 2012-029053
Patent Document 2: Japanese Laid-open Patent Publication No. 2012-085235
Patent Document 3: Japanese Laid-open Patent Publication No. 2011-223118
However, with the technologies described above, if, for example, a wireless area collected by a person has occurred, quality information is excessively collected and thus the size of a storage device that stores therein the quality information collected from the terminal device becomes enlarged. Consequently, there is a problem in that the capital investment in improving the wireless quality is excessively increased.